The Assessment of Cardiac Rehabilitation on Echocardiographic Parameters of Left Ventricular Systolic Function in Patients Treated by Primary Percutaneous Coronary Intervention due to Acute ST-Segment Elevation Myocardial Infarction: A Randomized Clinical Trial

Background: The exact effects of cardiac rehabilitation on the left ventricular (LV)
systolic function have still remained controversial.
Objectives: The aim of this randomized clinical trial was to assess the effects of cardiac
rehabilitation on echocardiographic parameters of LV systolic function in patients
treated by Primary Percutaneous Coronary Intervention (PPCI) due to acute ST-segment
Elevation Myocardial Infarction (STEMI).
Patients and Methods: After estimating 50 patients as the total sample size according
to previous studies and type of the current study, the patients with acute STEMI who
were treated by PPCI in our academic centers and had LV ejection fraction (EF) of 35
- 49% were divided into two groups via permuted block randomization method. The
first group (n = 25) underwent an 8-week comprehensive cardiac rehabilitation program.
Meanwhile, the controls (n = 25) were just instructed on risk factor management. All
patients underwent echocardiographic examination during the first week after acute
STEMI and 10 weeks later. The measured parameters included LVEF, stroke volume
(SV), LV end-diastolic diameter/volume (LVEDD/LVEDV), LV end-systolic diameter
(LVESD/LVESV), fractional shortening (FS), LV mass, and mean global longitudinal LV
strain (εLL). The SPSS, version 18.0, was used for data analysis and P values less than 0.05
were considered to be statistically significant.
Results: The mean age of the participants was 53.68 ± 6.9, ranging from 38 ± 71 years
old; 58% of the patients were men with an approximately similar distribution in both
groups. The comparison of changes in variables before and after the rehabilitation period
between exercise and control groups illustrated a significant increase in LVEF (mean
percentage changes: 13.56 ± 15.98% vs. 2.86 ± 8.46%; P = 0.005) and mean global εLL
(16.39 ± 14.97% vs. 2.62 ± 9.98%; P < 0.001) in the rehabilitated individuals. In addition,
a significant decrease in LVESD (-7 ± 8.98% vs. -0.53 ± 6%; P = 0.004), LVESV (-10.48 ±
11.86% vs. -2.5 ± 12.34%; P = 0.025) and LV mass (-6.06 ± 6.65% vs. -1.30 ± 6.37%; P =
0.013) was observed in the exercise group as compared with the controls. No significant
change in FS, LVEDD and LVEDV was occurred between the groups during the
rehabilitation period.
Conclusions: Early exercise-based cardiac rehabilitation program in patients
revascularized by PPCI after acute STEMI could have beneficial effects on LV systolic
function with no adverse effect on LV remodeling.